My theory: Younger generations of men (after Gen X) do not shower as often as generations before them, or potentially - know how to shower properly. You have to clean everywhere.
I also wouldn't assume they know how to properly wash clothes and linens - especially washcloths (if they use them) and towels. The little pod doesn't take the germs away. So everything, after a while, can have an odor.
There are a lot of families without dads to teach in modern society, and hardly any school has Home Econ. anymore where the Home Econ. teacher goes over detergent vs. bleach, how to wash your whites, etc.
I personally find women who do not wash their hair for days gross.